Meeting 9-4-2015 Aaron J. Cole WDNR Senior Fisheries Biologist - PowerPoint PPT Presentation

Pipe Lake Meeting 9-4-2015 Aaron J. Cole WDNR Senior Fisheries Biologist Barron & Polk counties Aaron.Cole@Wisconsin.gov 715-637-6864 FISHERIES MANAGEMENT ……….… we make fishing better

Sampling • Fyke Netting (Apr. 4 to Apr. 10, 2015) – Walleye (marking), northern pike • Early spring shocking (Apr. 10, 2012) – Walleye (recapture) • Bass daytime shocking (marking for PE) (Apr. 28-30, May 4, 26- 27, 2015) – Largemouth bass and smallmouth bass • Late spring shocking (June 1-2, 2015) – Bass (recapture), bluegill, black crappie • Fall shocking (in a couple weeks) – Walleye recruitment (Age-0 and Age-1 walleye) – Largemouth bass

Walleye size(lakes combined) 30 N = 200 25 Unknown Male Frequency 20 Female 15 10 5 0 8 10 12 14 16 18 20 22 24 26 28 Length (in)

Adult (≥15 in ) Walleye population estimates 3.0 Adult density (fish/acre) Density (fish/acre) 2.5 Lakes combined: 0.8 Pipe Lake: 0.7 2.0 N. Pipe Lake: 1.4 1.5 1.0 0.5 0.0 1985 1990 1995 2000 2005 2010 2015 2020 Year

Northern pike size structure 8 7 6 Unknown Frequency Male 5 Female 4 3 2 1 0 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Length (in)

Bluegill size structure 120 100 N=333 Pipe Lake: 186 fish/mile 80 Frequency North Pipe: 147 fish/mile 60 40 20 0 3 4 5 6 7 8 Length (in)

Largemouth Bass size structure (marking) 120 N=729 100 Frequency 80 60 40 20 0 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Length (in)

Adult ( ≥8 in ) largemouth bass population estimates 14.0 12.0 Density (fish/acre) 10.0 8.0 6.0 2004: 2015: 7.7 fish/acre 10.1 fish/acre 4.0 2.0 0.0 2002 2006 2010 2014 Year

Catch rates of ≥8” largemouth bass in fall surveys 12 10 8 Fish / mile 6 4 2 0 2007 2008 2009 2010 2011 2013 2014 Year

Early Conclusions • Good water quality but low fertility • Low density walleye population (0.8 fish/ac), but typical for Polk County lakes • Maintain 18” walleye length limit and 3 fish daily bag limit • Continue alternate year large fingerling walleye stockings-10 fish/acre

Early Conclusions • Has maintained a high density largemouth bass population • Increased harvest of 9- 14” largemouth bass will improve size structure • Will continue annual fall shocking surveys – Assess bass and walleye

Black Crappie Sarcoma

Barron & Polk distribution

What we know • Know very little about BLC sarcoma… • Results open raised sores on the skin • Diagnosed as small round cell tumor – sarcoma (malignant tumor of fish) • We think a virus may trigger the tumor • Currently advise not to eat – DISCARD infected fish!

Current testing • Picture of fish, blood, skin, muscle, gill, heart, kidney, spleen, liver, lesion – Histology (the study of microscopic anatomy of cells) • Maine – Electron microscopy (EM; used to visualize the virus) • Madison – Virology (study of viruses) • La Crosse – Next generation sequencing (used to identify virus) • Florida

Questions? Aaron J. Cole WDNR Senior Fisheries Biologist Barron & Polk counties Aaron.Cole@Wisconsin.gov 715-637-6864 FISHERIES MANAGEMENT ……….… we make fishing better